There has been known that a homoepitaxially grown film surface of diamond is likely to have defects, such as abnormally grown particles, macrobunching, and etch pits, formed thereon.
Those defects deteriorate the device performance. With regard to other materials, the planarization of the surface in the device performance is very important, and those defects need to be suppressed in a device to be prepared in device fabrication using diamond.
There is a report on the formation of a step-terrace structure on a diamond (001) substrate at a methane concentration of 0.025% using microwave plasma CVD (see Non-patent Document 1).
However, such a flat surface cannot be obtained on a (111) substrate. The device fabrication using diamond, therefore, needs a technique of selectively forming n flat surface of the device size.
Meanwhile, with regard to other materials, it is known that a mesa surface is formed atomically flat by carrying out chemical vapor deposition (H2 (4400 cm3/min), SiH4 (2.7 cm3/min), C3H8 (0.3 cm3/min), 1600° C., 20 mbar for 30 minutes) after forming a mesa structure on SiC substrate (see Non-patent Document 2).
It is also known that a mesa surface is formed flat by carrying out deposition at a substrate temperature of 850° C. with a supersonic beam Si2H6 as a source material after forming a mesa structure on Si (111) substrate (see Non-patent Document 3).
Further, it is known that a mesa surface is made atomically flat by carrying out metalorganic vapor phase epitaxy after forming a mesa structure on a GaAs (111) B substrate using SiO2 mask (see Non-patent Document 4).
Non-patent Document 1: H. Watanabe, D. Takeuchi, S. Yamanaka, H. Okushi, K. Kajimura, T. Sekiguchi, Diamond and Related Materials 8 (1999) 1272-1276.
Non-patent Document 2: J. Anthony Powell, Philip G. Neudeck, Andrew J. Trunek, Glenn M. Beheim, Lawrence G. Matus, Richard W. Hoffman, Jr., and Luann J. Key, Growth of step-free surfaces on device-size (0001) SiC mesas, Applied Physics Letters Vol. 77 (2000) 1449-1451.
Non-patent Document 3: Doohan Lee, Jack M. Blakely, Todd W. Schroeder and J. R. Engstrom, A growth method for creating arrays of atomically flat mesas on silicon, Applied Physics Letters Vol. 18 (2001) 1349-1351.
Non-patent Document 4: Toshio Nishida and Naoki Kobayashi, Step-free surface grown on GaAs (111) B substrate by selective area metalorganic vapor phase epitaxy, Applied Physics Letters Vol. 69 (1996) 2549-2550.